Primer for internal combustion engines



Oct. 3, 1967 1.. H. TUGGLE PRIMER FOR INTERNAL COMBUSTION ENGINES Filed Aug. 21, 1964 6 v e. M w! W mam 7 4: J Q f 485 United States Patent 3,345,045 PRIMER FOR INTERNAL COMBUSTION ENGINES Lloyd H. Tuggle, Maquoketa, Iowa, assignor to Clinton Engines Corporation, Maquoketa, Iowa, a corporation of Michigan Filed Aug. 21, 1964, Ser. No. 391,117 2 Claims. (Cl. 26134) This invention relates to a primer for assisting in starting an internal combustion engine and has particular reference to a primer adapted for use on an engine having a carburetor of the type having a float bowl containing a body of liquid fuel and a fuel nozzle leading from the float bowl to the fuel air mixture passageway of the carburetor.

The primer of the present invention comprises a pneumatic air pumping device such as a flexible bellows, or bulb, communicating with the float bowl above the level of the fuel therein and having a vent opening therein through which the float bowl is normally vented to atmosphere. The bellows is adapted to be manually depressed or deflated and the vent opening therein is positioned so as to be covered up by the fingers of the operator, thereby raising the pressure in the float bowl and pumping a measured amount of fuel through the fuel nozzle into the mixture passage of the carburetor.

A principal object of the invention is to provide a new and improved primer for assisting in starting an internal combustion engine.

Another object of the invention is to provide a manually operable pneumatic air-pumpnig device in conjunction with a float bowl carburetor for pumping a measured amount of fuel into the induction system of an engine to assist in starting the engine.

A further object of the invention is to provide a primer of the type described in which the pumping device need not be located near a source of fuel, but may be located at any place on the engine or remote therefrom and connected to the source of fuel by a flexible tube.

A further object of the invention is to provide an engine-priming device which is simple in construction, easy to operate and which forces a measured amount of fuel directly into the induction system of an engine upon actuation thereof.

Other and further objects of the invention will .be apparent from the following description and claims and may be understood by reference to the accompanying drawing, of which there is one sheet, which by way of illustration shows a preferred embodiment of the invention and what I now consider to be the best mode of applying the principles thereof. Other embodiments of the invention may be used Without departing from the scope of the present invention as set forth in the appended claims.

The single figure of the drawing is a sectional view illustrating a carburetor of the float-bowl type having a primer according to the present invention. The carburetor is of conventional construction and includes a body casting 12 having a fuel air mixture passage 14 therein and a float bowl 16 secured to the body 12 by a threaded plug 18, which is threaded into the lower end of a downwardly extending tubular portion 20 of the body 12. The float bowl containsliquid fuel up to approximately the level indicated at 22 and the proper fuel level is maintained by a float 24, which is secured to an arm 26 pivotally mounted on a pin 28. a

The carburetor body 12 has a liquid fuel inlet 30 which communicates with the float bowl 16 through a valve seat member 32 having a passage 34 therein adapted to be closed by a valve member 36 which rests at its lower end on a portion 38 of the float mounting arm 26. A fuel nozzle 40 extends upwardly through the portion 20 of the carburetor body 12 and opens into the passage 14 in the region of the venturi with which carburetors of this type are conventionally provided. An adjustable needle valve 42 meters the amount of fuel flowing upwardly through the passage 44 in the fuel nozzle 40. The fuel passage 44 is in communication with the float bowl through a passage 46 in the carburetor body 12. A conventional idle fuel passage 48 is also provided. Other details of construction and operation of the carburetor are conventional and are not illustrated herein.

The float bowl 16 is provided with an air inlet 50 above the level of the fuel therein and a flexible tube 52 communicates the interior of the float bowl with an air pumping device such as a flexible bellows 54. The bellows 54 is provided with a vent opening 56 through which the float bowl is vented to atmosphere. The bellows 54 may be mounted directly upon the carburetor if desired, or may be mounted at any other place on the engine and connected to the float bowl by the flexible tube 52.

In order to provide the rich mixture needed for starting the engine, the bellows 54 is manually depressed and the opening 56 therein is positioned so as to be covered by the operators fingers at such time so that depression will increase the pressure in the float bowl above atmospheric pressure to cause a measured amount of fuel to flow from the float bowl upwardly through the fuel nozzle 40 into the mixture passage 14.

The term bellows is used herein to include any hollow resilient device such as a bulb which can be squeezed or manually depressed to pump air into the float bowl to raise the pressure therein. A primer of this type has many advantages over conventional methods of providing a rich mixture for starting an engine such as the use of a choke in the carburetor air passage, since the primer provides a measured amount of fuel and thereby prevents flooding or starving of the engine, and the flow of air to the engine is not impeded by the conventional choke valve and its operating shaft.

While I have illustrated and described a preferred embodiment of my invention, it is understood that this is capable of modification, and I therefore do not wish to be limited to the precise details set forth but desire to avail myself of such changes and alterations as fall within the purview of the following claims.

I claim:

1. In an internal combustion engine having a carburetor for supplying the engine with a rich fuel-air mixture during priming and with a leaner mixture during normal operation, the carburetor being of the type provided with a float bowl adapted to contain a body of liquid fuel and a body of air normally under atmospheric pressure above the fuel level, the carburetor having a body with a fuelair mixture passage and a fuel nozzle for conducting fuel from the float bowl to the mixture passage therein; a primer for aiding in starting the engine comprising a manually operable bellows having a vent opening therein, said float bowl having an air inlet above the fuel level and a tube running between said air inlet and the interior f said bellows and establishing free air flow communication therebetween so that during normal operation of the engine said float bowl is vented to atmosphere through said tube and bellows, and said bellows being manually depressible and said vent opening therein being positioned so as to be covered by the operator as said bellows is depressed thereby increasing the pressure in the float bowl and causing fuel to flow through said nozzle into said mixture passage so as to prime the engine during starting thereof.

2. In an internal combustion engine having a fuel supply container adapted to hold a body of liquid fuel and a body of air normally under atmospheric pressure above 3 the fuel level, a carburetor for supplying a rich fuel-air mixture during priming and a leaner mixture during normal operation, the carburetor being of a type including a fuel-air mixture passage in the body thereof leading from atmosphere to the engine intake manifold, and a fuel supply passage for supplying fuel from the supply container to the mixture passage; a primer for aiding in starting the engine comprising a manually operable bellows having a vent opening therein, said supply container having an air inlet above the fuel level and a primer tube running between said air inlet and the interior of said bellows and establishing free air flow communication therebetween so that during normal operation of the engine said fuel container is vented to atmosphere through said primer tube and bellows, and said bellows being manually depressible and said vent opening therein being p0- sitioned so as to be covered by the operator as said bellows is depressed, thereby increasing the pressure in the fuel container and causing fuel to flow through said fuel supply passage into said fuel-air mixture passage so as to prime the engine during starting thereof.

References Cited UNITED STATES PATENTS HARRY B. THORNTON, Primary Examiner.

RONALD R. WEAVER, Examiner. 

1. IN AN INTERNAL COMBUSTION ENGINE HAVING A CARBURETOR FOR SUPPLYING THE ENGINE WITH A RICH FUEL-AIR MIXTURE DURING PRIMING AND WITH A LEANER MIXTURE NORMAL OPERATION, THE CARBURETOR BEING OF THE TYPE PROVIDED WITH A FLOAT BOWL ADAPTED TO CONTAIN A BODY OF LIQUID FUEL AND A BODY OF AIR NORMALLY UNDER ATMOSPHERIC PRESSURE ABOVE THE FUEL LEVEL, THE CARBURETOR HAVING A BODY WITH A FUELAIR MIXTURE PASSAGE AND A FUEL NOZZLE FOR CONDUCTING FUEL FROM THE FLOAT BOWL TO THE MIXTURE PASSAGE THEREIN; A PRIMER FOR AIDING IN STARTING THE ENGINE COMPRISING A MANUALLY OPERABLE BELLOWS HAVING A VENT OPENING THEREIN, SAID FLOAT BOWL HAVING AN AIR INLET ABOVE THE FUEL LEVEL AND A TUBE RUNNING BETWEEN SAID AIR INLET AND THE INTERIOR OF SAID BELLOWS AND ESTABLISHING FREE AIR FLOW COMMUNICATION 